Did you ever measure a smell? Can you tell whether one smell is just twice strong as another? Can you measure the difference between two kinds of smell and another? It is very obvious that we have very many different kinds of smells, all the way from the odor of violets and roses up to asafetida.
But until you can measure their likeness and differences, you can have no science of odor. If you are ambitious to find a new science, measure a smell.
^Persaud, Krishna; Dodd, George. Analysis of discrimination mechanisms in the mammalian olfactory system using a model nose. Nature. 1982, 299 (5881): 352–5. PMID 7110356. doi:10.1038/299352a0.